I just bought a iphone 4 a month ago. Bluetooth and wifi connected fine to a Getac pocket PC with win mobile 6. Last Saturday the connections just didn't happen. As MANY others have stated, bluetooth on the iphone is continually searching and never finds nearby devices. The pocket PC found and connected to my buddies Droid and worked find.
MY SOLUTION IS TO BUY A DROID.
I too have had annoying problems with bluetooth on my iphone 4. My 3gs was flawless. Never a problem with the device connecting or clarity.
With iphone 4 my Bose headset often won't connect when I turn it on. I have ot go into the iphone for settngs, turn bluetooth OFF, wait, then turn it back on, then click the devide to get it to connect. Such a pain.
I also have had regular complaints of sounding muffled, etc.
PLEASE APPLE FIX THIS!